I was typing into the library search bar and happened to be watching the resource count.
I typed the letter e and noticed the resource count decreased; (OK my mind was not focussed on what it should have been!)
Out of curiosity, I wondered which resources would not have an 'e' in them, given that particular letter's fame for being the most commonly used in English.
I tried * ANDNOT e to see what they were and saw unexpected results. As far as I can see, these resources have the letter e in their title:

As I say ... not important just curious 